It's not like Seid has much of a choice.
His main task is to look after Seraphine, anyway. Whether she's inside or outside of the castle, he has to do what Eric ordered him to and watch over her wherever she goes. She's not really supposed to leave the palace, though. That's part of their deal with Merlin.
But, again, Seid doesn't have much of a choice.
Seraphine is already on the roll. There's nothing that can stop her at this point.
"Please, little lady, think about the consequences. Both you and Master might get in trouble for this. You may have a chance of succeeding, but if that doesn't happen, you'll end up making things worse."
Even though she's already unstoppable, he still continues to try to reason with her.
